The electronic products are required to include a frequency to be an operation clock of electrical signals due to the demand of operation of the electronic products. Therefore, the oscillator is one of the significant components for the electronic products. However, the frequency, internal voltage, current or impedance of the quartz crystal unit within the oscillator may not be satisfied the specification due to the cutting of the quartz crystal unit or other customizing requirements. Therefore, the oscillator is calibrated by an external signal calibrator.
Most of the current signal calibrators are designed by asynchronous signal interface. The programmer will write a target frequency parameter which is required to be corrected with an oscillation frequency of the programmer itself into the oscillator. However, since the frequency and the phase of the oscillation frequency signal of the programmer is different from that of the oscillation frequency signal of the oscillator, and the single one electronic pin of the oscillator cannot process the target signal parameter outputted from the programmer and the oscillation frequency signal of the programmer at the same time. Therefore, it is necessary to design an additional electronic pin of the oscillator to receive the oscillation frequency signal of the programmer, and the frequency of the target signal parameter and the frequency of the oscillation frequency signal of the programmer perform the asynchronous process within the oscillator so as to guarantee that the target signal parameter can be written into the oscillator correctly. However, the additional pin of the oscillator will increase both of the chip area of the oscillator and the cost of the oscillator.